82 



INDIVIDUALITY IN ORGANISMS 



In agamic reproduction in plants each new individual 

 arises as a localized region of growth and the growing 

 tip is the first region to become clearly defined. New 



'^i\: 



a 



31 



'A 



-OJl 



33 



34 



Figs. 30-34. — Planaria doroto- 

 cephala: Fig. 30, structure of ali- 

 mentary tract and arrangement of 

 central nervous system; a, b, two 

 regions indicating pieces for reconsti- 

 tution; Figs. 31-33, stages of reconsti- 

 tution; Fig. 34, side view of early 

 stage. 



buds, new roots, and other parts arise in this way in 

 nature and under experimental conditions. The small 

 outgrowths along the sides of the growing stem-tip in 



